About 200,000 years ago Homo sapiens evolved into the modern humans we are today. Humans has been through some much change over the last 200,000 years. From the elements of mother nature to the tech savvy world of today, humans has evolved and will continue to evolve. Humans have gotten taller, faster, and bigger over time which is evidence that humans are still evolving. I will be discussing the evolution of some of the main organs that has helped us survive over the last 200,000 years.
The Evolution Of The Brain
The brain has been a vital part of the evolution of humans. As humans evolved the human brain has tripled in size with most of its growth occurring in the past two million years. (Hawks, 2013) For the first two-thirds of human history, the size of the brain was within the range of those of other apes living today. (Hawks, 2013) The final third of our brain has seen the greatest growth in size. Starting with the Homo habilis, the brain grew in size and also saw growth in the language-connected part of the frontal lobe. As we evolved into Homo sapiens, so did the brain. The brain continued to grow in size. As society evoluted and became more structured, the brain evolved and adapted to the changes. “The shape changes we see accentuate the regions related to depth of planning, communication, problem solving, and other more advances cognitive functions.”(Hawks, 2013) However, over the last 10,000 years the brain size has gotten smaller. Scientists has attribute the lack of nutrients to this trend. With new push for nutrients and better eating the brain size has actually increased in size over the years. The brain has evolved and will continue to evolve has our culture evolve.
The Evolution Of The Heart
The heart is another vital organ in a our survival. The heart has four pumping chambers, two atria and two ventricles. The atria receives blood coming into the heart and than the ventricles receives the blood from the atria and then pumps into other areas of the body. The right side of the heart gets the blood from the body and sends it to the lungs. The left side of the heart receives the fresh blood from the lungs and than sends it to the rest of the body. Finally there are arteries which leaves the heart carrying the blood to its destination. So how did the heart evolve into this complex organ? The diagram above shows the evolution of the heart and its chambers. (Kerk, 2010) Scientists has determined that the human heart resembles closely to that of fish, amphibians, and reptiles at some stages of their development. So even before the evolution of humans the heart was already beginning to evolve. So has organisms evolved from fish to amphibians, from amphibians to reptiles and from reptiles to mammals, so did the heart evolve to what we know today.
The Evolution Of The Reproductive Organs
Finally the most important part of organisms is the ability to reproduce. But how does a single organism evolve into an organism that can sexually reproduce? The first organisms were part of asexual reproduction, which means when they produce they were able to pass everything down to their offspring. However, humans reproduce sexually which means it takes two to reproduce. This part of the evolution process confuses evolutionists. If we evolve from single-cell organisms, why don’t we use the process of asexual reproduction? There are several